Method of making a wound package and after-treating the same



METHOD OF MAKING A WOUND PACKAGE AND AFTER-TREATING THE SAME O. A.BATTlSTA Filed July 10, 1948 Aug. 4, 1953 m. H ET m W m A f m PatentedAug. 4, 1953 UNI-TED? stares Orla-ndovA; Battista, Drexel'sHilLuBaassignor to American-v Viscose. Corporation,. Wilmington DeL, a.corporationmf Delaware Application J icy-:10, 1948, Serial No. 38,133

1 This inventiomrelatesz' torraamethodzof handling woundipackagesixor'cakes'rofi filamentary material comprising regenerated:cellulose: from viscose; and or a? novel/shrinkable? wrappers adapted?to be? applied to: the: cakesxprior: tossuch handling; Freshlye'spunregeneratedsceilu'losesiromeviscose is'zsubjected'v toi a" seriesofitafteretreating; liquids, including; bleaching and: desulfidingliquids; finally wash'edtiwith water; and: drie'di. In the conventional:practice, tli'evfilamentary material procee'ding from: the: spinning:bath is collected in: centrifugal spinningzbiickettto? form; a: so:-cazlledt rayonf cake andziscthen". after=treated and dfiedfinzthe:ca'kertfonns Theiaiteretreated and mashed regeneratednceilirlose issin: theiform: of: a: highly swollen" gel, comprising. from: 2.001%;tor500%-5 by weight of water. The moisture; content-of; thercake-is:.-re duced to at least 7 to 12% during drying;v,and

asithcszwater is?removed;therfilamentary material 1 andipaperwrappersxhaverbeen proposed iforthis:

One':=0f...thedifiicuities' in processing the cakes has: been theproblem ofi providingr, them; with at. wrapper; WhiC'h'Wi-HQ accommodatethecake while the filamentary imaterial-isdn \theextended waters-swollencondition" resultingtfrom the liquid. treatmcnt; and then. shrinkiwithrthe cake: as the watenisz-removed therei-rom' during the drw ingrstenWhen the cake draws raw-aye from. the wrapper: during 1: dry;ing,-.,vthe-wrapper is too loose for; the: dried cake: and: slips? relatively-01- thecake, Imaking; it\ difficult? to! handle=and z tendingtordisturb. the thread layers] at-l the: outer and inner, surfacesoix-"ther-cake; Additionally, the ends: OfEKthQ WI'aJODGI' are =tuckedinter-tithe hollow center of; the: cake and (when the r wrapperv doesmat-shrink:-with-nthes cake; the 1005812611115 not the wrapper. occupy;thee centem ofz the. dried: cakeand-make it: difilcultcforrthetoperatorr. to slip the cake without damaging,v the wrappen. 011..perfo: ratednrodst on tubes suchiasareeused in suppnrte s- Claimsa(cits-155.29

ingthescake. during dyeingthereof. in: aisubse-r quent ope-ration.

Itlisa primary, object.oflthisiinvention to providv a wrapper'forprotecting woundjpackages of regenerated cellulose from viscose duringcone a; rayon cake-which isz-rinexpensivei and can: be thrownuaway? afterrone use: without L substantially increasing 1 the: cost: of:producing: :the thread; A further: object .is to'providera'shrinkablecprotecttive wrappenrwhichiisistrongzenorugh ton witha standprocessing conditionssas IWeH'faSL-th'e moderatelyc rough handling; towhich: the: processed cake is'ssubjectedr during-shipment: to. aarewind; ing;.twisting'rorvotherr textilerworlcirrgfi device.

Theobjects of; the invention 3 are accomplished by providing; the-rcakes; i after-: collection?- of the filamentarymaterial and priorwto.liquid; processa ing with a:1iquidapermeableiprotective*papmelikecoveiaor wrapper comprising fiberss-of asamaterialwhichne'not:affectechas: such by 'aqueous' saponb fyingrmedia and fibersofz'ar-celluloser ester; the fiberswbeingz: bcndedctogethern and! thefibers" in the: wrapper: occurring initially; im a: condition ofpotential unbalance, whereby, when: the wrappedr package is"; treatedwith: an" aqueous saponifying medium to decrease'cthe?ester:-content ofthe wrapper. by; removal 2 of; ester." groups; the celluloseresterfibersmrewfree tosshrink and-draw theremainingfibersrwith:them toncausecockfling of such remaining fibers, with shrinkageiofr the wrapper as:a; whole: and: acquisition Of! a crepe effectr thereby:

Thef-wrapper. is: placed' on: the cakeewhicm is them subjected to. theliquid; aiteretreatments'; including an aqueous: saponifyinge, medium;washed anddriedi as by; centrifuging; or by exeposure towarmair currentsor the: like;

The: cellulosevesterafibers; fromz-whiclr thesester groups are vre'movedby; the wsaponiiying medium, shrinkor contractwhen. the cake: is";dried, and due to. the condition of potential unbalanceioi the fibers,shrinkagewof;the deeesterified fibers causes therremainingfiberstocockleor: buclclei Shrinkage-0f ther wrapperioccurs--simultaneouslyywith shrink ageof: thencake 0f,- regenerated'cellulose; during: drying; and, aftervcompletion. of therdrye ingz;operation; the shrunlc wrapper: fits closely against the: inner: andouter peripheries or, the cake:

By conditionr of potential: unbalance" of; the fibers is: meant any;relation of. the fibersv such that the' cellulcse ester fibers/arefreeeto shrink and]:draw theeremaining'.fiberstwith them. Thepotential:unbalancevmawbe due: torthecpresence of? a: preponderance of!the cellulose: ester: fibers? oriramdom idistribu-tion 'ofzthefibersvin. th'eYpIO'dI-F uct, ,onitmayybevdue -to--the= occurrence thosefibersixat on on .the-:-surface-I- 0161a" thin feltr-likeguorpaperi-likec .base; either atzlocalizedis areas t of: the

surface; ortat .allxrportions'soff' theatsurface; ,or! both;providcdthatrwl'iem the esterrfib'ersxoccurratsthie 3 surface there isnot such intermingling of the fibers that shrinkage of the celluloseester fibers would be opposed by the tendency of the remaining fibers toresist the shrinkage.

If the wrapper comprises a thin liquid-permeable paper-like product suchas a thin felt-like product formed from a mixture of the two types offibers, such' as may be obtained by commingling the fibers by any of theknown methods, for example, carding, deposition from an inert fiuidconveying medium, etc., in order to insure the condition of potentialunbalance the cellulose ester fibers must be present in an amount of atleast 25%, and in the range of 55 to 70%, if the fibers areparallelized, 25 to 70% if the fibers occur in random disposition.

If the wrapper comprises a paper or paperlike product formed from thefibers of a material which is not affected as such by the aqueoussaponifying media, and the cellulose ester fibers occur at the surfaceonly, the cellulose ester fibers must be present in an amount not lessthan 7% by weight, and may be present in an amount of from 7% to 50% byweight, or more.

The de-esterification of the cellulose ester fibers may be partial orcomplete, with partial or. complete reconstitution of the cellulose.

I have found that the aqueous alkaline solutions commonly used at thedesulfiding stage in the after-treatment of regenerated cellulosethreads effect a sufficient decrease in the ester content of the wrapperto result in the desired shrinking and creping thereof during the dryingstep. The removal of the ester groups to render the wrapper shrinkableupon drying while it is in place on the cake can be effected, therefore,without modification of the conventional aftertreating procedures.

The invention is illustrated in the accompanying drawing in which Fig. 1illustrates diagrammatically means for practicing one embodiment of theinvention;

Fig. 2 illustrates means for practicing another embodiment;

Fig. 3 shows a tubular cake wrapper in accordance with one embodiment ofthe invention;

Fig. 4 shows an annular cake of thread having a wrapper in accordancewith the invention, the cake being shown in the extended conditionresulting from the liquid after-treatments, including treatment with anaqueous saponifying agent and washing, but prior to drying; and

Fig. 5 shows the cake after the drying operation, the wrapper being, asshown, creped and shrunken with the cake due to shrinkage of thede-esterified cellulose ester components.

The cellulose ester fibers may be in the form of discontinuous fibers,bundles of such fibers obtained by cutting or chopping a continuousfilament yarn to the desired lengths, or a continuous filament orfilament yarn may be distributed on the surface of the paper in apattern such that the cellulose ester fibers occur locally on the paper.The term cellulose ester fibers as used herein is intended to includesuch fiber bundles as well as the fibers or filaments per se. Thecellulose ester fibers may be bonded to the surface of a finished paperin any appropriate manner. If the cellulose ester is in plasticizedcondition, the paper on which they are distributed is heated, preferablyunder pressure, for example by passing it between heated calender rolls,to convert the cellulose ester to adhesive condition and bind fibers inthe product together. In another embodiment, the cellulose ester fibersare bonded to the surface of the paper by means of a solvent for theester, for instance, acetone, when the ester is cellulose acetate. Whenthe cellulose ester fibers are deposited on the surface of a web of theother fibers, for example cellulose fibers, as a step in the manufactureof paper, they may be anchored to the surface by autogenous bonding ofthe fibers, or they may be bonded to the surface of the paper by meansof a thin, continuous film of a film-forming material such asregenerated cellulose which is not itself affected by the saponifyingagent used subsequently to remove ester groups.

A web of cellulose ester fibers may be deposited on the paper, eithercontinuously or discontinuously, during the course of its manufacture,as shown in Fig. 1, which illustrates more or less diagrammatically thatportion of a paper making machine located in general proximity to thehead box. Referring to Fig. 1, the paper making wire screen I travelscontinuously and in the direction of the arrows under idling roll 2,around roll 3, through head box 4 and between the rollers 5 and I4. Awater suspension of paper-making fibers of a material which is notaffected as such by aqueous saponifying media for cellulose esters flowsinto the head box 4 through inlet 6, toward the continuously travellinginclined wire screen and, as the fibers reach the screen they aredeposited on it, the water passing through the screen to a collector 1,and being returned to the system through the pipe 8. The fibers thusdeposited on the screen are represented by fine lines 9. The sheet ofpaper is not completely formed until it reaches the point In which isthe point of contact of the level of the fiber suspension with themoving screen. From point [0 the paper passes on to be finished in theusual manner.

At point I l, above the level of the fiber suspension in the head box, asuspension of cellulose ester fibers l2 in water is fed into the box,through an inclined trough l3, which may be provided with baffles ifnecessary. The outlet of trough l3 extends completely across the screenso that the suspension of cellulose ester fibers (indicated by the heavylines I2) is deposited on the web across the width of the screen. Theoutlet end of the trough may be provided with an automatically operatedtrap door or the like, (not shown) to permit deposition of thesuspension of plasticized cellulose ester fibers on the web of otherfibers carried on the screen at spaced intervals along the web. Thecellulose ester fibers are laid down on the surface of the alreadyformed web, and occur on the surface with little penetration of thecellulose ester fibers into the web, and minimum intermingling of thetwo types of fibers.

The structure comprising the cellulose ester fibers is dried by passingit between heated rollers l5 and I6, and is then passed between therollers I1 and I8 heated to the temperature at which the plasticizedcellulose ester fibers are converted to a tacky adhesive condition,whereby the cellulose ester fibers are autogenously bonded to the paperfibers. The structure is then cooled, for example by subjecting it tocold air currents, to set the fibers in the bonded relation. The paperis then formed into a tube or sleeve-like member to provide the cakewrapper. The tube may be formed by overlapping the edges of the papersheet, and subjecting the overloaded edges to heat and pressure wherebythe cellulose ester fibers which occur at the edge are again activatedto tacky condition, and bonded together to seal the edges. The tubularwrapper is then slipped over the rayon cake. to-be after-treated, theends of the wrapper being tucked into the hollow center of the cake, andthe wrapped cake is treated with the after-treating liquids, includingan aqueous sa-poniiyingv medium, which may also. be a desulfiding mediumfor the thread, such as an aqueous solution of about 6.0% sodium sulfideand 0.5% sodium carbonate, finally washed, and dried, as

by centrifuging followed byexposure to circulat-v ing warm air currents.

As an example, when the Wrapped filamentary material is'desulfided usingthe solution or'sodium sulfide and sodium carbonate mentioned above, ata temperature of 40-45" C. for one-half hour, and the paper cake wrappercomprises 20% of cellulose acetate fibers, the percent combined aceticacid in the cellulose acetate component of the wrapper drops from 54 to30%, and the wrapper shrinks correspondingly during the drying Step,with the development of crepe effects.

If unplasticixed cellulose ester fibers are laid down on the web carriedby the travelling wire screen of the paper-making machine, they may bebonded to the surface by spraying or otherwise treating the paper with asolvent, or the paper may be provided with a thin film of afilm--forming material, preferably regenerated cellulose, which willanchor the cellulose ester fibers to the paper, Means for practicingthis embodiment of the invention is illustrated diagrammatically in Fig.2, only a portion of the apparatus being illustrated, and the web I9carrying the cellulose ester fibers 20 being shown as it passes from thetravelling wire screen of Fig. 1. As an illustrative example, thestructure carried by the screen may comprise 80% by weight of cellulosefibers and 20% by weight of cellulose acetate fibers, the ester fibersbeing in the form of bundles obtained by cutting or chopping 300denier/80 filament cellulose acetate yarns having a twist of 2 turns perinch. The structure is dried by passing it between the heated calenderrolls 2| and 22 which also serve to press the cellulose ester fibersagainst the web consisting of the other fibers. An aqueous solution ofviscose of from 2 to 5% concentration is extruded onto the surface ofthe web carrying the ester fibers through the extrusion device 23, afterwhich the product is passed through the vessel 24 containing an aqueoussulfuric acid coagulating and regenerating bath which regenerates thecellulose. After drying the paper carrying the cellulose ester fibersand regenerated cellulose film in any suitable manner, a suitable lengthof the paper is formed into a tube and sealed along its edges. Forexample, one edge may be brushed with a solution of cellulose acetate inacetone, and lapped over the other edge, the acetone evaporated, and theoverlapped edges subjected to heat and pressure to seal them together.

A tubular cake wrapper in accordance with the invention is shown in Fig.3, the cellulose ester fibers being in the form of bundles or yarnlengths distributed on the surface of the wrapper in a series ofparallel strips or ribs 25. It will be understood that the celluloseester fibers may occur at all portions of the surface of the paper base,the proportion of cellulose ester fibers being not less than 7% byweight. The upper limit for the cellulose ester fibers is not critical,but generally those fibers are used in an amount in the range of 7% upto 50%.

As shown in Fig. 4, the tubular paper wrapper is placed over the cake.When the cake is after-treated by liquids including an aqueoussaponifying medium for the cellulose ester, the

ester groups are: removed, and the wrapper shrinks with the cake duringthe drying step, As shown in Fig. 5, the wrapper which fitted closely tothe water-expanded liquid treated cake of Fig. 4, also fits closelyagainst the surfaces of the dried and shrunkencake. Examples of, thecellulose ester fibers which may be used, in. plasticized. or.unplasticized. condition, are fibers of cellulose acetate, cellulosepropionate, cellulose butyrate, and mixed cellulose esters such ascellulose ace.tate-butyrate..

Fibers of a material which is not affected as such by the saponifyingmedium, and suitable for makin the paper arenatural fibers such as wood,cotton, hemp, linen, abaca, or synthetic fibers such as regeneratedcellulose fibers obtainable from viscose or cuprammonium. Such fibersmay be of regular paper-making length or theymay be longer than normalpaper-making length.

Generally, the alkaline desulfiding liquid which isalso a saponifyingagent for the cellulose ester comprises an aqueoussolution of sodiumvsulfide which may or may not contain a small amount of other alkalineagents such as, for instance, sodium carbonate. However, other saponifying agents may be used, if desired, and. it is within the scope of theinvention. to treat the wrapped cake with a saponifying medium, at astage separate from the desulfiding treatment, and prior to the finalwashing step.

If desired or necessary, the paper wrapper may be provided with 'amultiplicity of minute holes for increasing the porosity of the wrapper,prior to placing it over the thread cake.

The cellulose ester fibers may be activated by heat or the solvent tothe point where they flow to form a film which is adhered to the surfaceof the paper, but preferably the fibers remain in essentially fibrousform in the wrapper. However, after the drying step, neither type offiber occurs in its original condition, the de-esterified celluloseester fibers being shrunken, with cockling of the remaining fibers toproduce the creped effect.

The bonds between the fibers obtained by converting the cellulose esterfibers to adhesive condition by heating and then cooling the product toset the fibers in the bonded relation are not disturbed by theafter-treating liquids. The fibers remain fixed in the bonded conditionthroughout the after-treatments and the drying step. The dried wrapperin which the fibers are unified by coalescence, i. e. by cellulosebonds, exhibits good tenacity and the dry Wrapped cake can be handledwithout tearing of the wrapper. Since the Wrapper shrinks with the cake,it can not slip relatively of the cake after the drying, and. thisfacilitates handling of the cake and prevents damage to the exposedlayers of the cake due to brushing of the Wrapper thereagainst. Sincethe wrapper fits closely against both the inner and outer peripheries ofthe cake, the center of the cakes is left free to receive the rods orthe like on which the wrapped cakes are supported for subsequentprocessing such as dyeing.

By a "liquid permeable paper-like cover or wrapper as used herein, ismeant any permeable sheet material such as paper or thin felt-likeproducts having good wet strength and of sulficient thinness andflexibility to be readily conformed generally to both the inside andoutside peripheral surfaces of an annular thread or yarn package.

The above description and examples are intended to be illustrative only,and not to limit the scope of the invention. Any departure therefromwhich conforms to the spirit of the invention is intended to be includedwithin the scope of the appended claims.

I claim:

1. The method comprising distributing from about 20 to 50% by weight ofcellulose ester fibers on a surface of an unperforated and unslittedsheet of liquid-permeable paper formed from cellulose fibers, said esterfibers being distributed only at spaced portions of the sheet, renderingthe cellulose ester fibers adhesive and subjecting the sheet to pressureto obtain a sheet in which the ester fibers are autogenously bonded tothe cellulose fibers, wrapping the unperforated sheet about all surfacesof an annular package of regenerated cellulose filamentary materialfreshly prepared from viscose, treating the wrapped package with aqueousafter-treating liquids including an aqueous alkaline solution which is adesulfiding agent for the filamentary material and a saponifying agentfor the cellulose ester to simultaneously desulfide the filamentarymaterial and at least partially de-esterify the ester, finally washingthe wrapped package, and thereafter heating all portions of the wrappedpackage to thereby (1) dry the filamentary material with shrinkage ofthe filamentary package and (2) shrink the sheet of bonded cellulosefibers and de-esterified cellulose ester fibers with the package.

2. The method of claim 1 in which the fibers 8 distributed on the sheetof cellulose fibers are cellulose acetate fibers and they aredistributed in spaced parallel strips.

3. The method of claim 1 in which the desulfiding agent is an aqueoussolution of sodium sulfide.

4. The method of claim 1 in which the desu1 fiding agent is an aqueoussolution of sodium sulfide and sodium carbonate.

ORLANDO A. BATTISTA.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,847,269 Schur Mar. 1, 1932 1,912,625 Dreyfus June 6, 19331,961,914 Richter et al. June 5, 1934 1,968,356 Schmidt July 31, 19342,012,723 Lockhart Aug. 27, 1935 2,159,704 Levey May 23, 1939 2,208,653Whitehead July 23, 1940 2,208,965 Dousma July 23, 1940 2,382,400 Deckeret al. Aug. 14, 1945 2,414,833 Osborne Jan. 28, 1947 2,477,000 OsborneJuly 26, 1949 2,528,129 Francis, Jr. Oct. 31, 1950 FOREIGN PATENTSNumber Country Date 502,045 Great Britain Mar. 10, 1939

1. THE METHOD COMPRISING DISTRIBUTING FROM ABOUT 20 TO 50% BY WEIGHT OFCELLULOSE ESTER FIBERS ON A SURFACE OF AN UNPERFORATED AND UNSLITTEDSHEET OF LIQUID-PERMEABLE PAPER FORMED FROM CELLULOSE FIBERS, SAID ESTERFIBERS BEING DISTRIBUTED ONLY AT SPACED PORTIONS OF THE SHEET, RENDERINGTHE CELLULOSE ESTER FIBERS ADHESIVE AND SUBJECTING THE SHEET TO PRESSURETO OBTAIN A SHEET IN WHICH THE ESTER FIBERS ARE AUTOGENOUSLY BONDED TOTHE CELLULOSE FIBERS, WRAPPING THE UNPERFORATED SHEET ABOUT ALL SURFACESOF AN ANNULAR PACKAGE OF REGENERATE CELLULOSE FILAMENTARY MATERIALFRESHLY PREPARED FROM VISCOSE, TREATING THE WRAPPED PACKAGE WITH AQUEOUSAFTER-TREATING LIQUIDS INCLUDING AN AQUEOUS ALKALINE SOLUTION WHICH IS ADESULFIDING AGENT FOR THE FILAMENTARY MATERIAL AND A SAPONIFYING AGENTFOR THE CELLULOSE ESTER TO SIMULTANEOUSLY DESULFIDE THE FILAMENTARYMATERIAL AND AT LEAST PARTIALLY DE-ESTERIFY THE ESTERFINALLY WASHING THEWRAPPED PACKAGE, AND THEREAFTER HEATING ALL PORTIONS OF THE WRAPPEDPACKAGE